It may help to retrain Siri to recognize your voice. Please try the steps below then let us know if it helps.
How to retrain Siri
- Open Settings on your iPhone.
- Scroll down and select “Siri & Search.”
- Look for the toggle switch for “Hey Siri” and turn it off. Wait 10 seconds.
- Turn it back on again.
Your iPhone will ask you to train Siri to recognize your voice. Tap continue and follow the prompts, speaking slowly and distinctly.
One final note, to make sure Siri hears you when you say, “Hey Siri,” open Settings > Siri & Search and make sure that Listen for Hey Siri is set to On. You can also select Press Side Button for Siri if you prefer to get her attention that way.